1. Field of the Invention
The present invention relates to a polishing pad, in particularly, to a polishing pad having a groove structure for avoiding the polishing surface stripping.
2. Description of the Related Art
FIG. 1 shows a conventional polishing pad having grooves extending in direction XY. The conventional polishing pad 1 has a plurality of grooves 11 which are perpendicular to one another. Other conventional polishing pads may adopt a design of grooves in different shapes, mostly extending in direction XY or other variations thereof, and the pattern of the grooves is fabricated according to certain specifications.
In regard to the cutting size of the conventional polishing pad 1 and the pattern of the grooves 11, due to the geometric design, smaller grinding areas 12 may be formed at the outmost edge of the conventional polishing pad 1. The smaller grinding areas 12 generally have an acute structure, which is liable to scratch the polishing article. Further, in the course of a grinding process, the conventional polishing pad 1 suffers a downward pressing force to closely abut against the polishing article. At the same time, the conventional polishing pad 1 moves in a horizontal direction, so as to grind the polishing article to-and-fro. However, since the grinding areas 12 at the outermost portion of the conventional polishing pad 1 are smaller and have the acute structure, the grinding areas 12 suffer the greatest centrifugal force during the grinding process. When moving in the horizontal direction, the conventional polishing pad 1 in frictional contact with the polishing article suffers a greater shear stress, and is thus liable to peel off from the base material and become small grinded pieces, which impairs the grinding quality and the grinding effect.
Consequently, there is an existing need for providing a polishing pad having a groove structure for avoiding the polishing surface stripping to solve the above-mentioned problems.